Toner for developing electrostatic images, developer, image forming method, and image forming apparatus

Abstract

The object of the present invention is to provide a toner which has sufficiently high chargeability and less toner spent to a carrier or the like even when several tens of thousands of image sheets are output, is capable of keeping high-charge property and flowability without causing substantial background smear or toner fogging, excels in low-temperature fixing property and hot-offset property, and has a wide range of fixing temperature as well as to provide a developer, an image forming apparatus, a process cartridge, and an image forming method using the toner for developing electrostatic images. The toner of the present invention comprises a colorant, and a resin, and a fluoride compound, in which the fluoride compound exists on the surfaces of toner particles, and the atomic number ratio (F/C) of fluoride atoms to carbon atoms existing on the surfaces of the toner particles is 0.010 to 0.054.

1. A toner for developing electrostatic images comprising:
 a colorant, 
 a resin, and 
 a fluoride compound, 
 wherein the fluoride compound exists on the surfaces of toner particles, and the atomic number ratio (F/C) of fluoride atoms to carbon atoms existing on the surfaces of the toner particles is 0.010 to 0.054. 
 
     
     
       2. The toner for developing electrostatic images according to  claim 1 , wherein the toner is formed by dispersing oil droplets of an organic solvent with a toner composition containing a prepolymer dissolved therein in an aqueous medium, and subjecting the dispersion to an elongation reaction and/or a cross-linking reaction. 
     
     
       3. The toner for developing electrostatic images according to  claim 1 , wherein the toner comprises a polyester resin. 
     
     
       4. The toner for developing electrostatic images according to  claim 1 , wherein the toner comprises a modified polyester resin. 
     
     
       5. The toner for developing electrostatic images according to  claim 1 , wherein the toner comprises an unmodified polyester (ii) along with the modified polyester (i), and the weight ratio of the modified polyester (i) to the unmodified polyester (ii) is 5/95 to 80/20. 
     
     
       6. The toner for developing electrostatic images according to  claim 1 , wherein the fluoride compound is a compound represented by General Formula 1: 
       
         
           
           
               
               
           
         
         where X represents —SO 2 — or —CO—; R 5 , R 6 , R 7 , and R 8  is a group individually selected from the group consisting of hydrogen atoms, alkyl groups having carbon atoms of 1 to 10 and aryl groups; “m” and “n” is an integer; and Y is a halogen atom such as I, Br, and Cl. 
       
     
     
       7. The toner for developing electrostatic images according to  claim 1 , wherein the toner particles are formed in a substantially spherical shape with an average circularity E of 0.90 to 0.99. 
     
     
       8. The toner for developing electrostatic images according to  claim 1 , wherein the circularity SF-1 value of the toner particles is 100 to 140, and the circularity SF-2 value of the toner particles is 100 to 130. 
     
     
       9. The toner for developing electrostatic images according to  claim 1 , wherein the volume average particle diameter Dv of the toner particles is 2 μm to 7 μm, and the Dv/Dn ratio of the volume average particle diameter Dv to the number average particle diameter Dn is 1.15 or less. 
     
     
       10. The toner for developing electrostatic images according to  claim 1 , wherein the fluoride compound is contained in a content of 0.01% by weight to 5% by weight relative to the total weight of the toner. 
     
     
       11. A method for producing a toner for developing electrostatic images comprising:
 dispersing a fluoride compound in alcohol containing water, and 
 making the fluoride compound adhere on or bound to the surface of the toner, 
 wherein the toner comprises a colorant, a resin, and a fluoride compound, the fluoride compound exists on the surfaces of toner particles, and the atomic number ratio (F/C) of fluoride atoms to carbon atoms existing on the surfaces of the toner particles is 0.010 to 0.054. 
 
     
     
       12. A two-component developer comprising:
 a toner for developing electrostatic images, and 
 a carrier which comprises magnetic particles, 
 wherein the toner for developing electrostatic images comprises a colorant, a resin, and a fluoride compound, the fluoride compound exists on the surfaces of toner particles, and the atomic number ratio (F/C) of fluoride atoms to carbon atoms existing on the surfaces of the toner particles is 0.010 to 0.054. 
 
     
     
       13. An image forming apparatus comprising:
 a photoconductor, 
 a charging unit configured to charge the photoconductor, 
 an exposing unit configured to expose the photoconductor charged by use of the charging unit with a write laser beam to form a latent electrostatic image, 
 a developing unit with a developer loaded therein configured to develop the latent electrostatic image into a visible image by supplying the developer to the photoconductor to thereby form a toner image, and 
 a transferring unit configured to transfer the toner image formed by use of the developing unit onto a transferring member, 
 wherein the developer is a two-component developer which comprises a toner for developing electrostatic images and a carrier; the toner for developing electrostatic images comprises a colorant, a resin, and a fluoride compound, the fluoride compound exists on the surfaces of toner particles, and the atomic number ratio (F/C) of fluoride atoms to carbon atoms existing on the surfaces of the toner particles is 0.010 to 0.054; and the carrier comprises magnetic particles. 
 
     
     
       14. An image forming method comprising:
 charging a photoconductor, 
 exposing the photoconductor charged in the charging unit with a write laser beam to form a latent electrostatic image, 
 developing the latent electrostatic image into a visible image by supplying the developer to the photoconductor to thereby form a toner image, and 
 transferring the toner image formed in the developing onto a transferring member, 
 wherein the developer is a two-component developer which comprises a toner for developing electrostatic images and a carrier; the toner for developing electrostatic images comprises a colorant, a resin, and a fluoride compound, the fluoride compound exists on the surfaces of toner particles, and the atomic number ratio (F/C) of fluoride atoms to carbon atoms existing on the surfaces of the toner particles is 0.010 to 0.054; and the carrier comprises magnetic particles. 
 
     
     
       15. The image forming method according to  claim 14 , wherein the transferring comprises transferring the toner image formed on the photoconductor onto an intermediate transfer member, and transferring the toner image on the intermediate transfer member onto a final transfer member. 
     
     
       16. A process cartridge comprising:
 a photoconductor, and 
 one or more units selected from 
 a charging unit configured to charge the photoconductor, 
 a developing unit with a developer loaded therein configured to develop a latent electrostatic image formed by means of exposure into a visible image by supplying the developer to the photoconductor to thereby form a toner image, and 
 a cleaning unit configured to remove a residual toner remaining on the photoconductor after transferring, the one or more units are integrally supported so as to be detachably mounted on the main body of an image forming apparatus, 
 wherein the developer is a two-component developer which comprises a toner for developing electrostatic images and a carrier; the toner for developing electrostatic images comprises a colorant, a resin, and a fluoride compound, the fluoride compound exists on the surfaces of toner particles, and the atomic number ratio (F/C) of fluoride atoms to carbon atoms existing on the surfaces of the toner particles is 0.010 to 0.054; and the carrier comprises magnetic particles.